Method and apparatus for editing motion picture film

ABSTRACT

A motion picture film editing method and apparatus by which film portions to be deleted during projection are indicated by signals recorded on a fixed record track attached to a cassette housing the film. A scanning transducing head is provided in the projector and advanced in synchronism with the film advance mechanism to sense the recorded signals and control film advance speed in a manner such that the portions of the film to be deleted are fed at high speeds past the projector light path whereas those to be viewed are fed at normal speeds. Also, the light path is blocked during passage of the deleted film portions therethrough.

[54] METHOD AND APPARATUS FOR EDITING MOTION PICTURE FILM [75] Inventor:John F. Batter, Jr., Lincoln, Mass.

[73] Assignee: Polaroid Corporation, Cambridge,

Mass.

221 Filed: Ju1y17,1970 21 Appl.No.: 55,735

[52] US. Cl ..352/38, 352/78 C, 352/180 [51] Int. Cl. ..G03b 21/48 [58]Field of Search ..352/38, 17, 78 C, 180

[56] References Cited UNITED STATES PATENTS 2,905,048 9/1959 Miller..352/38 3,580,667 5/1971 Moore ..352/24 3,288,550 11/1966 Saraber..352/180 3,301,628 l/1967 l-Iellmund ..352/92 X 3,389,953 6/1968 Gerry..352/78 3,539,248 11/1970 Lancor ..352/17X '42 se 46 l l 1, 44 .1 7e{I}, 82 so 78 [111 3,724,935 14 1 Apr. 3, 1973 3,492,927 2/1970 Thieleet al. ..352/78 C X Primary Examiner-Louis R. Prince AssistantExaminer-Frederick Shoon ABSTRACT A motion picture film editing methodand apparatus by which film portions to be deleted during projection areindicated by signals recorded on a fixed record track attached to acassette housing the film. A scanning transducing head is provided inthe projector and advanced in synchronism with the film advancemechanism to sense the recorded signals and control film advance speedin a manner such that the portions of the film to be deleted are fed athigh speeds past the projector light path whereas those to be viewed arefed at normal speeds. Also, the'light path is blocked during passage ofthe deleted film portions therethrough,

11 Claims, 6 Drawing Figures PATENTEDAPRS I975 3,724,935

SHEET 2 0r 2 .llllll' F G 6. A c SIGNA 3O L GENERATOR l 92 52 64 CONTROL48225 f CONTROL l k h SOLENOID g DETECTOR DR'VER INVENTOR JOHN F.BATTER, JR.

ATTORNEYS METHOD AND APPARATUS FOR EDITING MOTION PICTURE FILM CROSSREFERENCE TO RELATED APPLICATIONS BACKGROUND OF THE INVENTION Thisinvention relates to motion picture film editing and more particularly,it concerns a novel method and apparatus by which such film may beedited and prov jected without physical alteration of the film while atthe same time maintaining reasonable continuity in the projected imageto be viewed.

' In the aforementioned co-pending application, Ser. No. 55,736, (Case4075) there is disclosed a method and apparatus for editing motionpicture films which involves basically the recording of signals on atrack having a storage capacity corresponding in magnitude to the lengthof the film to be edited, the signals delineating undesired portions ofthe film to be deleted during projection from other portions of the filmto be viewed and employing such signals to effect an increase in filmadvance speed during the passage of deleted film portions through theoptical axis of the projector simultaneously with blockage of theprojection light during such passage. In the illustrated embodiments,the film itself is provided with a linear strip portion capable ofreceiving optical or electromagnetic signals and the projectionapparatus provided with transducing means for recording and sensingsignals on the track. The editing procedure is effected by imposing anAC signal, for example, on a film carried magnetic track tocorresponding to those portions of the film to be deleted while leavingunrecorded other portions of the track corresponding to those portionsof the film to be viewed. During projection, the head senses or detectsthe recorded signals and through appropriate control circuitry, bringsabout an increase in film advance speed which is maintained so long asthose portions of the film to be edited are passing through the opticalaxis of the projector. At the end of such portions to be deleted, normalprojection ratesare restored.

SUMMARY OF THE PRESENT INVENTION In accordance with the presentinvention, the basic motion picture film editing principles disclosed inthe aforementioned co-pending application are utilized but in a mannersuch that conventional motion picture film, devoid of any provision fora recording track thereon, may be edited efiectively without alteration,manipulation or physical contact with the film itself in any way.Specifically, a scanning transducing head driven in 'synchronism withthe film advance mechanism is positioned with respect to a fixedrecording track in such a manner that signals, recorded on the track todelineate undesired portions of the film to be deleted from view duringprojection, are used to achieve the desired change of film advancespeed. The present invention is particularly suitable for use withmotion picture film cassettes of the type insertable directly intoprojection machinery inasmuch as a contemplated embodiment involves themounting of the fixed recording track on an exterior surface of thecassette structure. 7

Among the objects of the present invention are: the provision of animproved method and apparatus for editing motion picture film; theprovision of such a method and apparatus which is readily adaptable toexisting forms of motion picture film cassettes; and the provision ofsuch a motion picture editing method and apparatus in which anymodification, alteration or contact with the film itself is totallyavoided.

Other objects and further scope of applicability of the presentinvention will become apparent from the detailed description to followtaken in conjunction with the accompanying drawings BRIEF DESCRIPTION OFTHE DRAWINGS FIG. 1 is a fragmentary side elevation in partialcrosssection depicting a motion film cassette in relation to thecomponents of a projection apparatus incorporating means for thepractice of the present invention;

FIG. 2 is an enlarged fragmentary cross-section taken on line 2-2 ofFIG. 1;

FIG. 3 is a fragmentary side elevation in partial crosssection showingthe opposite side of the film cassette illustrated in FIG. 1 in relationto other operating components of the projection apparatus of thisinvention;

FIG. 4 is a side elevation illustrating an exterior surface of themotion picture film cassette employed with the present invention;

FIG. 5 is a fragmentary cross-section taken on line 5-5 of FIG. 3; and

FIG. 6 is a block diagram of a control circuit for the practice of thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Although the presentinvention is adaptable to diverse general types of projection apparatus,reference is made to the accompanying drawings for exemplaryillustrations of embodiments of apparatus suited for the practice of theinvention. As shown in FIG. 1 of the drawings, a cassette generallydesignated by the reference numeral 10 is operably positioned in aprojector 12 having a projection lens 14. The cassette 10 includessupply and take-up spools 16 and 18 respectively, on which film F iscarried for movement about roller 20, past a film gate 22, aligned withthe optical axis of the projector as defined by the axis of the lens 14,and around a snubbing roller 24. Light for projection is supplied by alamp 26 positioned laterally of a triangular reflecting prism 28 toefiect projection of the filmimage through the lens 14 to a screen orother image receiving means (not shown).

Although many of the components of the projector 12 have been omittedfrom the drawing in the interest of clarity, it will be noted that drivemeans for advancing the film F between the respective supply and takeupspools 16 and 18 in the disclosed embodiment includes a variable speedelectric motor 30 having a multi-belt drive pulley 32 operably connectedby belts 34 and 36 to splined drive shafts 38 and 40 engagedrespectively with the spools l6 and 18. Although not shown in thedrawings, it will be appreciated by those skilled in the art that thecoupling of the drive including the belt 36 to the take-up spool 18 mayinclude conventional slip clutch and brake means. For example, the

belt 34 as depicted in FIG. 1 would not, in practice,

means carried by the projector 12 and including a reciprocable claw 46connected by a pin 48 to the eccentric 44. In accordance withconventional practice, the claw 46 operates to advance that portion ofthe film F extending between the roller 20 and the snubbing roller 24incrementally, frame by frame, past the gate 22. Though ordinarily theclaw 46 is maintained in a single operable relationship with respect tothe projector mounted cartridge, in the embodiment shown, the claw 46 isretractable against'the bias of a tension spring 50 by a solenoid 52which functions, when energized, to advance a link 54 slidably in atubular guide 56 between the positions depicted by solid and phantomlines in FIG. 1. Thus, in the solid line position maintained by thespring 50, the claw 46 is operative to advance the film F intermittentlyin the conventional manner. When the solenoid 52 is energized however,in

a manner to be described in more detail below, the claw 46 is retractedto the position illustrated in phantom lines so as to be out ofengagement with the film F. In accordance with the present invention,the projection equipment is provided with a movable blind 58 forblocking the passage of light through the gate 22 and the lens 14 duringediting of film strip portions. In the embodiment illustrated in FIGS. 1and 2 of the drawings, the blind 58 is carried slidably forreciprocationin guides 60 fixed to the projector 12 and maintainednormally in a retracted position clear of the optical axis by acompression spring 62, A solenoid 64 is provided to advance the blind 58against the bias of the spring 62 over the optical axis of the projector12 as defined by the lens 14..

In a manner which will become more apparent from the description below,the motor 30 and the solenoids 52 and 64 are controlled in response tosignals recorded on a track fixed with respect to the projector 12 andcorresponding in magnitude to the length of film to be edited;that is,the film F contained within the cassette in the disclosed embodiment.Inasmuch as the cassette 10 is fixed with respect to the projector onceit has been positioned operably therein, and in order that the recordedsignals may be correlated directly with the particular film strip to beedited, it is preferred that the track be fixed to the cassette 10itself. Thus, as shown in FIGS. 3-5 of the drawings, the aforementionedrecording track takes the form of a strip 66 carrying magnetic materialsimilar to that used in magnetic sound or information storage tapes andsuitably secured in an appropriate manner on an exterior surface of thecassette 10. In this context, it is to be noted that the strip 66provides a media on which magnetic signals can be recorded in a mannerwell known to those skilled in the magnetic recording art to provideindicia suitable for the practice of the present invention in the mannermore fully described below. Other forms of indicia can be employed,however, such as markings capable of being sensed by photoelectricmeans, physical alterations in appropriate material capable of beingsensed mechanically, and the like. Although the strip 66 may be securedto the cassette surface in various ways, it is preferred that the stripbe provided with its own pressure sensitive or other adhesive tofacilitate its being mounted on the cassette subsequent to themanufacture of the cassette itself.

With reference to FIGS. 3 and 5 of the drawings it will be noted that ascanning magnetic transducing head 68 is supported within the projector12 for movement along the track 66 (once the cassette 10 is operablypositioned in the projector) by a feed screw 70 rotatably supportedwithin the projector by bearings 69. The body of the head is providedwith internal threads (not shown) to engage the screw and to insurerelative rotation between the screw 70 and the head 68, the head isprovided with a pair of gears 72 engagable over guide rods 74 extendingthe full length of the track 66 and of the screw 70. In order that thehead 68 will be advanced along the screw 70 and thus along the track 66in synchronism with the advance of the film F by the feed claw 46, meansis provided in the projector by which the screw 70 will be rotated andthus the head .68 advanced incrementally once for each operation of theclaw 46 or one step for the passage through the gate 22 of each imageframe carried by the film F. In the embodiment shown, the means providedto serve this function take the form of a pawl 76 carried on theopposite side of the eccentric 44 from the side on which the claw 46 isconnected, and engagable with V a stepping ratchet 78 drivably connectedto the screw 70 through pinion gears 80 and bevel gearing 82. Because ofthe substantial gear reduction effected by this mechanism in conjunctionwith that afforded by the screw 70, it will be appreciated that the head68 will be stepped along the track through extremely small increments oftravel. Thus the length of the track 66, though corresponding to thelength of the film F, is substantially shorter than the film.

The head 72 is preferably of the read-write type, thereby beingoperative both to impose or record a signal on the track 66 and todevelop an electromag netic response to a signal previously recorded onthe track. It is contemplated that the projector 12 will carry thecircuit shown in FIG. 6 which includes, in addition to the head 68, anAC signal generator 84 operable by an appropriate control 86 to reorientthe magnetic characteristics of the track 66 over any portion thereofcorresponding to a portion of the film F. The signal thus imposed orrecorded on the track 66 may also be transduced by the head 68 and fedthrough an AC signal detector 88, a gate 90, to a motor speed controlunit 92 and to a solenoid driver 94. As depicted in FIG. 6, the motor 30is under the direct control of the speed control unit 92 and also, bothsolenoids 52 and 64 are energized simultaneously by the driver94. Thecontrol 86 is coupled to the gate 90 to prevent the passage of a signalto the motor speed control and solenoid driver during use of the ACsignal generator to place a signal on the track 66.

In the practice of the present invention employing a projector equippedwith the components described above, the cassette containing the filmstrip F to be edited is placed in the projector positioning the track 66relative to the transducing head 68 as shown in FIGS. 3 and 5 of thedrawings. The projector is then operated to view the film strip andascertain undesired portions thereof which should be deleted duringpresentation of the remaining portions of the film strip. When such aportion to be deleted passes the axis of the lens 14, the control 86 isoperated so that the head 68 will record on the track 66, a signalcorresponding to that portion of the film to be deleted.correspondingly, operation of the control 86 is terminated upon reachingthe end of the film portion to be deleted.

After the film F has been edited in the aforementioned manner, it isready for presentation to a viewer. During such presentation, thoseportions of the film F to be presented will be fed at normal projectionrates of feed by the drive motor 30 through its connection to theeccentric 44 of the intermittent drive claw 46 and to the take-up spool18. When, however, a signal is read or sensed by the transducing head68, thus indicating a portion of the film F to be deleted, the signal ispassed to the motor speed control 92 in the manner aforementioned toincrease the speed of the motor and effect a high rate of film advancespeed through the gate 22. Simultaneously with such increase in motorspeed and thus rate of film advance or feed, the solenoids 52 and 64 areactuated to retract the intermittent advance claw 46 and block passageof projection light through the lens 14 respectively. The head 68,however, will continue its advance along the screw 70 due to continuedoperation of the pawl 76 and ratchet 78. At the end of the deletedportion, the absence of a signal on the track 66 will terminateoperation of the signal detector 88, thereby effecting a return of themotor speed to that normally used for projection as well as a return ofthe claw 46 to its operative position by the tension spring 50 and areturn of the blind 58 to its retracted position by the compressionspring 62. In this manner, the presentation during projection of thefilm F to a viewer will include only those portions of the film that theeditor so desires to present. Although the presentation will beinterrupted slightly during the passage of the edited portions throughthe gate 22, the current state of the art with respect to electricmotors and controls therefor, as well as the low inertia of the limitedamount of film contained in the cartridge 10 permits that interval to bereduced to such a short duration of time as to be undetectable by thehuman eye.

Thus it will be appreciated that by this invention there is provided ahighly improved method and apparatus for editing motion picture films bywhich the above mentioned objectives are completely fulfilled. Ofparticular note, is the facility for editing motion picture film,provided by the present invention, by which no physical modification,alteration or contact with the film itself is required. Also, it will beapparent to those skilled in the art that various modifications and/oradaptations of the disclosed embodiment can be made without departurefrom the true spirit and scope of the present invention. Accordingly, itis expressly intended that the foregoing description is illustrativeonly, not limiting, and that the true spirit and scope of the presentinvention is to be determined by reference to the appended claims.

I claim:

1. The method of editing motion picture film comprising the steps of:recording signals on a track having a storage capacity corresponding inmagnitude to the length of the film to be edited, said signalsdelineating undesired portions of said film to be deleted from otherportions thereof to be viewed; advancing said film through a projectionaxis; advancing a signal sensing device along said track in synchronismwith said film advance, said track being fixedly positioned relative tosaid projection axis at least during said advancement of said film andsaid signal sensing device; and regulating the rate of film advance inresponse to said signals between normal projection feed rates duringpassage of said other portions through said projection axis andrelatively high feed rates during passage of said undesired portionsthrough said axis.

2. The method recited in claim I wherein said track is fixed to acassette containing the film.

3. The method recited in claim 1 including the step of blocking thepassage of light on said axis during advancement of said film at saidrelatively high feed rates.

4. Apparatus for editing and projecting motion picture film, saidapparatus comprising: means to establish a path of light through whichsaid film is passed for projection; means to establish a record trackhaving a storage capacity corresponding in magnitude to the length offilm to be edited; movable means for detecting signals recorded on saidtrack to delineate undesired film portions from desired film portions tobe projected; drive means for advancing said film through said lightpath, said drive means including means to advance said detecting meansalong said track in synchronism with the advance of said film throughsaid path of light, said track being fixedly positioned relative to saidpath of light at least during said advancement of said film and saidsignal detecting means; and means to control said drive means inresponse to said signal detecting means to advance said desired filmportions through said path at normal projection rates of feed and toadvance said undesired film portions through said path at a relativelyhigh rate of speed.

5. The apparatus recited in claim 4 including means to block said pathof light during passage of said undesired film portions therethrough.

6. The apparatus recited in claim 4 including a cassette containing saidfilm, said record track being mounted on an exterior surface of saidcassette.

7. The apparatus recited in claim 6 wherein said record track is amagnetic tape adhesively secured to the exterior of said cassette andwherein said detecting means includes a magnetic transducing head.

8. The method of editing motion picture film comprising the steps of:providing indicia along a track separate from said film and affixed to acassette containing said film, said indicia delineating certain portionsof said film intended not to be viewed during viewing operationsassociated with said film from other portions thereof intended to beviewed during such operations; progressively advancing said film througha projection axis; effecting relative motion between an indicia sensingdevice and said track in synchronism with said film advance; andregulating the rate of film advance in response to said indicia sensingdevice between normal viewing feed rates during passage of said otherportions of said film through said projection axis and relatively highfeed rates during passage of said certain portions of said film throughsaid axis.

means for providing indicia along a track separate from said film andaffixed to said cassette, said indicia delineating certain portions ofsaid film not to be viewed during viewing operations associated withsaid film from other portions thereof intended to be viewed during suchoperations; an indicia sensing device; means for progressively advancingsaid film through said axis; means for effecting relative motion betweensaid indicia sensing device and said track in synchronism with theadvance of said film through said axis; and means for regulating therate at which said film is advanced through said axis in response tosaid indicia sensing device between normal viewing feed rates duringpassage of said other portions of said film through said axis andrelatively high feed rates during passage of said certain portions ofsaid film through said axis.

11. The apparatus of claim 10 additionally including means forprecluding the passage of' light on saidaxis whenever said film is beingadvanced therethrough at said relatively high feed rates.

1. The method of editing motion picture film comprising the steps of:recording signals on a track having a storage capacity corresponding inmagnitude to the length of the film to be edited, said signalsdelineating undesired portions of said film to be deleted from otherportions thereof to be viewed; advancing said film through a projectionaxis; advancing a signal sensing device along said track in synchronismwith said film advance, said track being fixedly positioned relative tosaid projection axis at least during said advancement of said film andsaid signal sensing device; and regulating the rate of film advance inresponse to said signals between normal projection feed rates duringpassage of said other portions through said projection axis andrelatively high feed rates during passage of said undesired portionsthrough said axis.
 2. The method recited in claim 1 wherein said trackis fixed to a cassette containing the film.
 3. The method recited inclaim 1 including the step of blocking the passage of light on said axisduring advancement of said film at said relatively high feed rates. 4.Apparatus for editing and projecting motion picture film, said apparatuscomprising: means to establish a path of light through which said filmis passed for projection; means to establish a record track having astorage capacity corresponding in magnitude to the length of film to beedited; movable means for detecting signals recorded on said track todelineate undesired film portions from desired film portions to beprojected; drive means for advancing said film through said light path,said drive means including means to advance said detecting means alongsaid track in synchronism with the advance of said film through saidpath of light, said track being fixedly positioned relative to said pathof light at least during said Advancement of said film and said signaldetecting means; and means to control said drive means in response tosaid signal detecting means to advance said desired film portionsthrough said path at normal projection rates of feed and to advance saidundesired film portions through said path at a relatively high rate ofspeed.
 5. The apparatus recited in claim 4 including means to block saidpath of light during passage of said undesired film portionstherethrough.
 6. The apparatus recited in claim 4 including a cassettecontaining said film, said record track being mounted on an exteriorsurface of said cassette.
 7. The apparatus recited in claim 6 whereinsaid record track is a magnetic tape adhesively secured to the exteriorof said cassette and wherein said detecting means includes a magnetictransducing head.
 8. The method of editing motion picture filmcomprising the steps of: providing indicia along a track separate fromsaid film and affixed to a cassette containing said film, said indiciadelineating certain portions of said film intended not to be viewedduring viewing operations associated with said film from other portionsthereof intended to be viewed during such operations; progressivelyadvancing said film through a projection axis; effecting relative motionbetween an indicia sensing device and said track in synchronism withsaid film advance; and regulating the rate of film advance in responseto said indicia sensing device between normal viewing feed rates duringpassage of said other portions of said film through said projection axisand relatively high feed rates during passage of said certain portionsof said film through said axis.
 9. The method recited in claim 8additionally including the step of precluding the passage of light onsaid axis whenever said film is being advanced therethrough at saidrelatively high feed rates.
 10. Apparatus for projecting motion picturefilm comprising a cassette in which said film is housed: means forestablishing a path of light along a given axis; means for providingindicia along a track separate from said film and affixed to saidcassette, said indicia delineating certain portions of said film not tobe viewed during viewing operations associated with said film from otherportions thereof intended to be viewed during such operations; anindicia sensing device; means for progressively advancing said filmthrough said axis; means for effecting relative motion between saidindicia sensing device and said track in synchronism with the advance ofsaid film through said axis; and means for regulating the rate at whichsaid film is advanced through said axis in response to said indiciasensing device between normal viewing feed rates during passage of saidother portions of said film through said axis and relatively high feedrates during passage of said certain portions of said film through saidaxis.
 11. The apparatus of claim 10 additionally including means forprecluding the passage of light on said axis whenever said film is beingadvanced therethrough at said relatively high feed rates.